What’s New in Fusion 360: Event Simulation Analysis now available

We are excited to add Event Simulation Analysis to our list of supported study types in Fusion 360. Event Simulation Analysis in Fusion 360 is powered by the accurate and trusted Autodesk Explicit Solver and can be used to solve complex explicit dynamics and specific quasi-static problems.

Why perform an Event Simulation?

An Event Simulation study can be used to simulate time-dependent, dynamic events where the effects of velocity, acceleration, damping, and mass are essential. This is ideal for modeling problems that are transient in nature, involve large deformation, are contact dominated (Multi-body), involve impact, and/or have highly non-linear material behavior. Loads can be applied as a function of time, and results are output at actual instantaneous time points during the event, rather than at arbitrary increments in a static analysis.

The following list contains a few examples for which an Event Simulation might be appropriate:

Snap-Fit Assemblies

Drop Test

Impact Test

Crash Simulation

Key Event Simulation Features

Linear and rotational motion – Depending upon the application, you can simulate linear as well as rotational motion through Prescribed Translation/Rotation inputs as well as Initial Linear/Angular velocity inputs.

Contact dominated problems (Multibody) – You can automatically generate contact conditions for your Event Simulation study and modify their definition using the Contact Manager. You can also specify friction behavior between the different parts (default friction coefficient is zero) or specify that the contact surfaces are bonded together (default behavior is non-bonded/separable surface pairs). The contact modeling in Autodesk Explicit is completely general and does not require surfaces to be near each other. Autodesk Explicit solver continually monitors and tracks the proximity of the various free surfaces of the model, though all the large deformations and rotations to enforce the kinematic compliance of the parts when collisions are detected. One of the most versatile features of the contact detection algorithm is that it will automatically rebuild the surfaces of the model as material erosion occurs, and new surfaces are exposed due to element deletion.

Rigid Bodies – With a single declaration, you can specify that a part of the model is rigid. As a result, Autodesk Explicit solver will automatically compute the center of mass and all the rigid body properties for the part (e.g., mass moments of inertia and total mass) and compute the response of the part using rigid body dynamics equations. Since the part is rigid, it will not deform locally, meaning there will be no stress or strain in the part. Contact conditions will automatically be maintained between parts irrespective of whether or not a part is rigid. Best of all, rigid parts do not participate in the determination of the stable time step.

Non-linear material behavior and Large deformations – You can use Event Simulation to solve highly non-linear problems. Autodesk Fusion 360 already contains a Non-linear material library, and you can also add a new material with the non-linear material properties that you wish to apply to a model. The Autodesk Explicit solver is very well equipped to solve complex non-linear problems as well as can account for large deformations during the simulation.

Material deletion – Event Simulation allows you to define material deletion criteria that governs material failure and, thus, removal from the simulation. This is done by merely defining maximum value for the maximum principal strain that the material cannot exceed. Once the user-defined criteria are satisfied at a finite location in the model, the Autodesk Explicit solver removes the material at that location and deletes the corresponding element from the mesh. As elements are deleted from the model, Autodesk Explicit will automatically rebuild the contact surfaces where new material is exposed.

Quasi-static analysis – By Switching the “Movement” from Dynamic to Quasi-static (no inertia), you can obtain an approximate Quasi-static solution using the Explicit solver in Event Simulation. To get an approximate quasi-static solution in our explicit dynamics algorithm, we seek to make the magnitudes of the kinetic energy and viscous dissipation in the solution small compared to the magnitude of the internal energy and external work. Autodesk Explicit uses a proprietary algorithm to determine a duration for the simulation that is long enough that the kinetic energy is a small fraction of internal energy. The quasi-static algorithm will automatically scale all the time-dependent load curves for prescribed displacement boundary conditions and loads to fit in the time duration for the quasi-static solution. You are not required to “guess” a duration as Autodesk Explicit will determine this automatically.

Fusion 360 Answers the “What If”

All simulation attempts to answer the ultimate engineering question “What-if”. Now with Event Simulation, Fusion 360 can help you get your next project done, right the first time, without that nagging “What if” question hanging over your head. Even better, this study is solved using cloud computing freeing up your computer for other tasks and will only cost 15 Cloud Credits per solve. To familiarize yourself with Event Simulation tools and workflows, please refer to these Tutorials. To learn more about Event Simulation, please refer to our help page.

ABOUT THE AUTHOR

Rahul Patil is the Product Manager for Injection Molding and Mechanical Simulation Products. As Product Manager, Rahul drives the strategy and development efforts for Autodesk's Moldflow, Helius, Inventor Nastran and Fusion 360 Simulation Products. Rahul holds a Master's degree in Mechanical Engineering, specializing in Finite Element Analysis and Computational Fluid Dynamics and has over 5 years of experience with CAD and Simulation tools. In his spare time, Rahul enjoys playing soccer and riding his motorbike.

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